Hybrid electric vehicles employ an engine and an electric motor, which is operated by power supplied from a high-voltage battery separately installed on a vehicle, as driving sources for supplying a driving force. The hybrid electric vehicles are designed to realize optimal fuel economy by simultaneously or selectively driving the driving sources according to the circumstances.
The hybrid electric vehicles typically use an electric motor as a main driving source and an engine as an auxiliary driving source. Since an electric motor by nature generates remarkably little heat when driven compared to the engine, the hybrid electric vehicles are designed to conduct in-vehicle heating by driving the engine to heat a coolant of the engine.
In this regard, a “method of controlling a heating system for a hybrid electric vehicle” in Korean Unexamined Patent Application Publication No. 10-2007-0110603 discloses the method of controlling a heating system for a hybrid electric vehicle. Here, the hybrid electric vehicle includes a hybrid system control unit (HCU) controlling energy of the entire vehicle and others, a full automated temperature controller (FATC) controlling a heater to properly maintain an in-vehicle temperature, an engine control unit (ECU) controlling engine driving according to a start/stop instruction from the HCU, and an electric water pump for continuously supplying and circulating an engine coolant to a heater core. The method includes: a first step of collecting information about in-vehicle and open-air temperatures at the FATC and an operation of an engine at the ECU, and checking whether or not a request for heating is input by a user; a second step of determining whether or not the engine needs to be driven for heating on the basis of the information collected in the first step; and a third step of controlling driving of the water pump for heating when it is determined in the second step that the engine needs to be driven.
However, such a related art is designed to separately drive the engine for the purpose of in-vehicle heating. As such, a great deal of fuel is consumed to heat the coolant to a proper temperature, which leads to deterioration of total fuel economy of the vehicle.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.